


Dopamine

by Mthaytr



Category: Fullmetal Alchemist - All Media Types
Genre: D/s overtones, Light Bondage, M/M
Language: English
Status: Completed
Published: 2016-10-10
Updated: 2016-10-10
Packaged: 2018-08-20 13:38:38
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,940
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8251033
Author URL: https://archiveofourown.org/users/Mthaytr/pseuds/Mthaytr
Summary: Ed is not immune to his own biology, much to his dismay, and Roy isn't hard to convince.





	

**Author's Note:**

  * For [jujubee2522](https://archiveofourown.org/users/jujubee2522/gifts).



> This was commissioned by the lovely Jujubee on Tumblr, who wanted a fic based on "Dopamine," by Børns. I hope it was everything you wanted it to be!

He thinks that if he understands it, he will be immune: that by knowing the chemicals and their pathways, by understanding the physiological urges at their base level, he will be able to examine and dismiss his own.

Who has the time to indulge their bodies’ strange whims, after all: someone must, Ed thinks, but not him. Not until Alphonse has a body again. Not until he’s been cleansed; forgiven, as much as he can be.

So he studies; so he reads: _dopamine, oxytocin, serotonin,_ his blood boiling with desire that knows neither logic nor reason. So he looks away when Mustang fixes those dark eyes on him, tries not to feel them burning through his skin. So he spends nights gritting his teeth against the throb of heat collecting at his core, and curses his goddamn luck that his body had to fixate these natural desires on a man with such a smug fucking voice, a face that could launch a thousand ships if this were a myth, where beauty inspires heroism inspires greatness and against the instincts of his own biology he’s just one little dam in the course of a river ten thousand years in the making, and he doesn’t know how he can be expected to resist, but he does,

 _Oh_ he does

and hates Roy Mustang almost as much as he wants him, and they are flint and steel and if they are not very, very careful, the conflagration they create could consume them both.

And he recognizes the chemical processes at play in that, too: adrenaline, powering through his blood and making him bold despite his terror; norepinephrine, at work creating the thrill of his own brazenness, of the man’s attention, beside a thousand other invisible pathways and compounds still nameless, and all of it together mixing to form his words, his hunched shoulders, the sharp and fiery gleam in golden eyes.

The knowledge does not quell his anger, nor the ache in his loins, and when he, enraged and foolish, finally pulls the man down into a harsh, clumsy kiss, the knowledge that it is the dopamine making the contact between their skin catch and crackle like electricity through water doesn’t stop it from _burning._

He can’t close his eyes, too shocked at his own stupidity to prepare, and so he finds himself watching as the Colonel’s eyes widen — as his pupils blow suddenly outward like grenades — feels it with a heart-stopping intensity when the man’s hand comes to grasp at the back of his shirt, hears when the man makes a soft, terrible noise into the kiss, moves his lips against Ed’s for just a moment — 

— before he pulls away, and Ed remembers fear — remembers why _he wasn’t going to do this,_ remembers his futile attempts to keep this primal instinct at bay with closed eyes and a bitten lip and nights wasted alone with his hand, praying for some relief from his madness.

The distance between them turns to potential, and Ed can taste rejection out of the multitudes of electric possibilities, and why not? After all, rejection is just failure in micro scale, a personal level, and he’s had enough experience with the latter, at least,to know when it’s coming.

 _Ed,_ he says, brow pulled low over dark eyes. _Ed, we can’t._

Another shock of adrenaline, so quick and sharp and _cold_ it hurts like it’s tearing him open. He was ready for it ( _liar)_ and yet… ( _Is that a no? Is that a polite fuckin way of sayin **I don’t want you** , full stop? Or is it — )_

Before the adrenaline can coalesce into something more nebulous, more painful altogether, he scowls and says:

_Why the fuck not?_

Maybe it’s simple — maybe the chemical reactions that turn his blood to flame aren’t at work in Mustang’s; maybe they are, but he’s aware too of the distance between them, of Ed’s harsh edges and his inexperience and how he’s too much and not enough together, at once.

But maybe — if he’s lucky, and he never is, maybe all Mustang needs is permission. He clenches his jaw and holds on to that hope.

A shuddering laugh in return for the question; and what small miracles, Ed is close enough to feel it rumble through him, and he shivers, swallows, wonders if Mustang can feel his heartbeat pounding out through his ribs as powerfully. He doesn’t need this; no, he would live without it, but he’s learning that _want_ can be as powerful as _need_ sometimes and god, he does want it.

 _You’re fifteen, Ed._ Ed stiffens; a hand through his hair is nicer than he would have guessed, and that’s probably got something to do with the mindless currents in the ocean of his blood, too. 

_Thanks for noticing, asshat. And one of these days I’m prob’ly gonna punch your face in. Are we done stating the obvious, or you still have a few more to get in?_

Another laugh, tinged with desperation; the colonel throws his head back, and Ed takes the opportunity to push up onto his toes to taste the hollow at the base of the man’s throat, 

(his lips catch the fervor of the groan that follows, vibrating down to his core)

and Ed becomes suddenly aware of the hardness at Mustang’s front, pressed into him where he’s melded their bodies together to reach the parts of him he never could.

and then there is a hand clenching in his hair, and dark eyes sliding down to catch his, and the man uses his hold on it to pull Ed’s head back, merging their lips once more.

A murmured invitation; _this evening, please — my house, here’s my address_ — 

It doesn’t escape Ed that this gives the man all day to reconsider; he gets the same, of course, but this chemical madness is his drug and he’s an addict, and the instinctual parts of his brain have elected Mustang the man to feed it. There is no going back once he’s started.

 _(Please, please, if there’s any mercy in the universe, let me have this one thing.)_ He doesn’t deserve it, he knows, but still — this one good thing, to wipe away the memories of the bad just for a moment, isn’t so much to ask for, is it?

The day is hazy, a cocktail of want and nerves and heavy anticipation, and when he knocks at the colonel’s door, for a moment he’s afraid that no-one will answer — his stomach lurches — 

But there he is, cool still in his military blues, and Ed’s stomach finds its way up to his throat.

Squared shoulders and jaw; chin angled up to meet the man’s eyes.

 _You chicken out?_ he asks, a challenge; a smirk to accompany, baring teeth.

Another laugh from Mustang, and this one different from the others; each has its own nuance, its own motives, like together they make a language Ed finds he wants to learn.

He steps aside, waves Ed in, and no sooner has the door shut behind him than he’s on Roy like a spark on tinder, all teeth and tongue and bruising fingers — waiting for the man to make the first move would be _excruciating,_ and so he decides that he won’t.

And Roy fists helpless hands in Ed’s shirt, pulls their lips apart for a moment and says:

_You know we shouldn’t._

_Fuck that. Do you want to?_

And here he is, acting bold again, acting like he could handle it if Mustang said “no,” meeting the bastard’s eyes as if he’s strong and confident and the taste of his own fear isn’t sour in his mouth

Exhale. _God, Ed, you shouldn’t tempt me —_ his hands still moving across the cloth of Ed’s shirt, up his neck, and he looks startled by his own movements for a moment before that dark look from earlier makes itself known in Mustang’s eyes, and Ed is caught in a rush of realization — 

-that whatever protests come out his mouth, the man’s body gives him away; there is no space between them, and the Flame Alchemist’s body heat sears him, his lungs struggling against their new and startling weakness.

_C’mon, bastard — you gonna make me beg?_

A groan — head tilting back so he can pant at the ceiling — and then a gaze sliding down; then _focus,_ like a knife or maybe more like a blow because for a moment Ed loses his grip on the conscious world and when he comes to himself again, _he’s_ the one pinned to the door, the adrenaline scrawling words of fire through his blood. He barely has time to manage a startled breath through his parched mouth before the other man has sealed his own over it. Not long at all before Ed’s making tiny noises through his nose, tangling warm fingers in black hair, his automail slung around the man’s blue-gold striped epaulettes; not long again before the man pulls away and says, low, like the distant rumble of thunder — 

_Since I’m going to hell already, I certainly wouldn’t mind hearing you beg before I do._

For a moment, Ed forgets how to breathe; can no longer master this body or its contents, looking up into black, black eyes and their narrow gaze — narrowed to _him,_ to _them,_ and he’s spent so long fighting this but today, since that kiss, it’s been so hard to remember _why —_

He’s not fighting anymore. And neither, thankfully, is Mustang.

And that is where the thoughts end; after that there are hands, and mouths, and neurons sparking to life like fireworks — a graceless four-legged stumble of heat and mingled breath and pleasure sharp as his fear, sharp as the giddy danger of losing himself in the touch of another human being

Bed; bedsheets; Ed’s shoes come off; his clothes peel, layer by layer, and Mustang’s mouth makes its acquaintance with each swathe of skin revealed between. Murmured praise, a grateful priest’s benediction, for him, for _Ed,_ and he bites his lip as another man’s hot breath spreads out over his navel, below his rucked-up shirt, black eyes up through thick lashes.

_You are too damn tempting for your own good._

_Yeah?_ Breathless; hands under his shirt: oxytocin, serotonin in their wake. He lifts his arms up to allow the shirt off, but the cloth tangles around Ed’s wrists and suddenly Roy’s hand pins both of them to the mattress, a growl low in his throat 

_(Oh oh oh oh **fuck** )_

And why is it so hot, that predatory snarl, the _helplessness_ implied by the restriction of motion, knowing that he’s under the colonel’s control? There’s no logic to it, no decision born of reason and deliberate purpose, and why does he want _this_ when ( _what if you’re not good enough, what if you’re too much, what if)_ is the bass to the orchestra of sights and sensations that forms from the combination of their two frail bodies.

A high, shaky whine, formed in the shivering gap between body and soul; he arches to meet the solid heat of Roy’s thigh with his aching hardness.

 _Oh,_ the man says, smirk spreading out across his lips. _You like that._

It wasn’t a question, so Ed doesn’t answer: flips his head to the side to press his flush into his arm, although he has little hope of hiding it. Swallows nothing, herds his breathing to keep it steady, runs his tongue across dry lips.

Then comes the question; deceptively simple, with an answer that is anything but.

 _You want to stay like this?_ His free hand palms the bulge at the front of his pants mercilessly. _Do you want more? I can give it to you._

Exhale, eyes fluttering shut until there’s barely a gleam visible.

The cocktail of neurotransmitters and hormones that transcends his body has bent to those words long before reason or logic have a say. Words choke in his mouth, confounded by the terrible simplicity of _asking,_ so he just claps his hands together up above his head, where they belong; a crisp flash of blue, then his shirt begins to sink into the bed, tightening and flattening into hard cuffs, leaving him well and truly bound there.

The Colonel’s eyes widen; he drags in a breath, then presses a solid kiss to Ed’s sternum, ghosts them down to Ed’s navel, licking and suckling at the dip between, the heat between them _unbearable_.

The bindings around his wrists keep him barely tethered to this earth; thus confined, what can he do other than submit to the hands that are wiping him clean, each touch curing this sickness in his blood. 

There’s no room for fear _(you’ve always been a bad liar when it counts)_ as deft fingers begin the silent ritual of peeling the leather from his hips, his thighs, and however much he wants to move to cover himself, he _can’t —_ can’t hide from roving eyes or hands, can’t distract from the imperfections of his body with touch, warm or cool.

He grits his teeth when the man finally takes him in hand, whines deep in the back of his throat as a thumb comes to wipe away the bead of fluid at his tip, and he hadn’t expected it to be like _this,_ his dreams but pale shades of the reality of hands and tongues and small, wanting noises and this unexpected desireto give himself up to the man, to release his death grip on his own fragile control and let Mustang take care of it.

And once again the boundaries shift and there’s movement, Ed keening, oh oh _oh god — Colonel —_

And his own warm, sticky mess splatters out onto his stomach; he’s panting, oxygen an uncertain thing in this new world, and he’s not sure he could stand now even if he weren’t bound.

The smirk Roy wields in the aftermath is _devastating,_ and Ed bites his lip to keep a truly embarrassing noise buried within.

It’s just the dopamine, he knows, that makes him want to reach out and touch the man, to kiss him, independent of any more sexual acts. The way his heart warms and swells at the contact even though he’s naked and covered in his own fluids is oxytocin and not affection — which is good, perfect, because he knows that this ancient instinct is Mustang’s sole motivation, too.

Apparently the man has taken it upon himself to bring the boy’s attention back to the present by bending down, eyes still smoldering, and flickering his tongue out over the muscles of Ed’s stomach to lick him clean, and oh _fuck_ that’s hot, oh god — 

After an eternity, it’s back to his neck, and Mustang murmurs reassurances and promises into the curve of it, then tips Ed’s chin up to ask:

_do you want to keep going_

Swallowing, his pulse more a tremor than an echo of his heartbeat, he nods.

The process is a flood, a haze, a mess of heavy breaths and light touches — one finger first, a pain that loosens by the moment; two, then a third, then hooking up and _in_ and Ed _wails_ and arches up off the bed — — — Roy groans, slips an arm in underneath to hold him there — — — whispers beautiful impossibilities into sweat-slick skin; _oh you’re gorgeous, Ed, you don’t even know what you do to me — every day I can’t have you is like purgatory and you don’t even **know**_

And Ed shakes, pretends for a moment he believes the pretty lies, surrenders himself to sensation and his own wordless cries.

 _Can you unbind yourself?_ he asks, lips ghosting across the ridges of Ed’s ear. _Silly, perhaps, but I’d like your hands on me while I fuck you senseless._

Ed, overwhelmed, his guts blazing with want at every stroke, nods, and barely manages his promise — but he does, and tosses the shirt away, and encases the colonel’s body in his arms with an unspoken desperation.

Then they are one, as close as two creatures can be, and Mustang wraps his arms around Ed almost as tightly as Ed has, hardly an inch of them separate as he begins to move, his hips taking small motions and making them masterpieces, and now at least when they burn they burn _together._

When they finish, and Roy growls a noise Ed will never forget into his ear, Roy collapses beside him, and Ed barely needs to peek out from under the blankets to see the man’s wide, stupid grin.

_How are you feeling?_

_I don’t know._ Ed’s grin is as wide as Roy’s. _Good. A little… whoosh._ He adds an appropriate accompanying gesture to the ‘whoosh’. _But good._

A pause.

 _Amazin, maybe._ He hides his blush in the pillow, and Roy’s laugh is worth Ed’s momentary humiliation.

 _I sympathize. I, too, am feeling rather — whoosh._ He pulls Ed closer than could possibly be allowed, and now the grin is in his hair and he feels rather like light, coalesced.

 _That’d be the dopamine,_ Ed mumbles into the skin of Roy’s neck. _‘R maybe — oxytocin. Norepinephrine. One o’ those. Can’t ‘member right now — too sleepy._

 _Really,_ says Roy, the smile turning to a kiss laid on Ed’s forehead. _I beg to differ. I rather thought it was just — **you.**_

And Ed’s throat constricts, the sound of his heartbeat sudden and irregular in his ears, and here in the afterglow, he lets himself believe it.

 _Same difference in the end, though, in’t it?_ he says, even though his stomach is molten gold and he has the constellations tucked between his ribs.

_My dear, it makes all the difference in the world._

**Author's Note:**

> If you guys liked it, please let me know!!! It means a lot to me and helps keep me writing more filth ^^


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